1. Field of the Invention
The present invention relates to a novel compatibilizing agent capable of compatibilizing a radical copolymerizable unsaturated resin with an addition polymerized polymer which is added exclusively for purposes such as low profile and improvement of physical properties, a radical copolymerizable unsaturated resin composition, a molding material, and a molded article. More particularly, the present invention provides a compatibilizing agent which remarkably improves the compatibility between two components, i.e. a radical copolymerizable unsaturated resin (e.g. an unsaturated polyester, a vinyl ester resin and a vinyl urethane resin) and an addition polymerized polymer comprising a thermoplastic resin (e.g. polystyrene, poly(methyl methacrylate), a styrene butadiene rubber, polyvinyl acetate and an acrylic rubber), and which is very useful for solving problems of preservation and molding caused by poor compatibility. Furthermore, the present invention prevents these resin mixtures from separating, and makes it possible to convert the resin mixture into a stable dispersion state, that is, a homogenous resin mixture free from separation. The present invention, because of the above effects, provides a compatibilizing agent which makes it possible to attain a high value-added product, radical copolymerizable unsaturated resin composition, a molding material, and a molded article.
2. Description of the Related Art
Radical copolymerizable unsaturated resins are suitably used as raw resins for molding materials. However, molding materials using the radical copolymerizable unsaturated resin have a large problem in which volume reduction, which occurs on curing, causes warpage and cracks in the molded article. To overcome the problem, various thermoplastic resins, for example, low profile additives such as polystyrene, styrene-butadiene rubber and the like are used. However, since these low profile additives have poor compatibility with the radical copolymerizable unsaturated resin and separation after mixing is unavoidable, the resin mixture does not convert well into a homogeneous resin mixture free from separation because of its poor separation stability. In addition, in a molded article obtained from the above resin mixture, various defects in the appearance of the molded articles, such as scumming and segregation caused by separation of a low profile additive, often occur.
Thus, various methods of adding a stabilizer as a third component have been investigated. For example, U.S. Pat. No. 3,836,600 discloses an example where a styrene-ethylene oxide block copolymer prepared by a living anion polymerization method is used as the stabilizer. This stabilizer exerts a high compatibilizing effect and can maintain a stable dispersion state for a long period of time. However, it was difficult to mass produce the stabilizer industrially because of its special synthesis procedure.
On the other hand, a method of improving the compatibility by a procedure using an addition polymerized polymer introducing a vinyl acetate block, a saturated polyester block and the like into a low profile additive has been investigated (e.g., Japanese Unexamined Patent Application, First Publication No. Hei 3-174424 and Japanese Unexamined Patent Application, First Publication No. Hei 11-92646). These improved low profile additives have the effect of retarding the time required to separate, but a stable dispersion state is still to be obtained by essentially improving the compatibility. In addition, the above technology is limited to polymers having a particular structure, and therefore convenience of suitably selecting and using various types of addition polymerized polymer as a low profile additive depending on required physical properties, usage and the like, cannot be provided.
U.S. Pat. No. 3,94,7,422 provides a copolymer of styrene and half ester maleate of polyethylene glycol as a viscosity reducing agent which is added to a molding material, such as SMC and BMC obtained by using a vinyl ester resin. However, on converting into SMC, the remaining carboxyl groups from maleic acid, are absorbed to a filler such as calcium carbonate, and therefore the excellent compatibilizing effects for the purpose of the present invention can not be obtained. In addition, by an experiment in a system consisting of only unsaturated polyester and polystyrene without any filler, the present inventors have confirmed that there are some cases of exhibiting no compatibilizing effect. Therefore, conversion of many types of unsaturated resin and an addition polymerized polymer into a homogeneous resin mixture which is free from separation and scumming, uniform coloring properties, surface smoothness, gloss, and the like, of a molded article cannot be expected, while these are expected as effects of the present invention.
An object of the present invention is directed to essentially improve the compatibility between a radical copolymerizable unsaturated resin and an addition polymerized polymer (thermoplastic resin) which is added for the purpose of low profile and improvement of physical properties. Also an object of the present invention is to provide a compatibilizing agent which prevents molding defects caused by separation of the second component during the molding, or exhibit a stable dispersion state for a long period of time in the state of a resin mixed solution. That is, an object of the present invention is to provide a practical compatibilizing agent which makes it possible to convert the resin mixture into a homogeneous resin mixture free from separation and to eliminate defects (scumming, uniform coloring properties, surface smoothness and gloss) caused by separation during the molding by prevention of the separation between the radical copolymerizable unsaturated resin and addition polymerized polymer, which could not have been attained by the prior art, a radical copolymerizable unsaturated resin composition containing the same, a molding material, and a molded article.
The present inventors have intensively studied about these objects and found that a graft copolymer having a specific structure is very useful for the above compatibilizing agent, thus completing the present invention.
The present invention provides a compatibilizing agent for compatibilizing a radical copolymerizable unsaturated resin with an addition polymerized polymer, characterized in that said compatibilizing agent is a graft copolymer (A) which contains a styrene monomer as a principal component, and has a principal chain (A1) consisting of a copolymer with a (meth)acrylate monomer and a side chain (A2) selected from a ring-opening polymerized polyether side chain consisting of a polyoxyalkylene ether, a polyester side chain, and a polycarbonate side chain, the side chain (A2) being bonded to the principal chain (A1).
In the present invention, it is preferable to use a styrene monomer as a principal component which constitutes a principal chain (A1) of the graft copolymer (A) because of its excellent compatibilizing stability. In addition, the polyoxyalkylene ether, which constitutes a side chain (A2) in (A), is preferably a polyether containing oxyethylene units as a principal component. It is preferable in view of performance and synthesis that the number-average molecular weight is within a range 1,000-20,000, and more preferably 2,000-10,000. The present invention preferably provides a very useful radical copolymerizable unsaturated resin composition characterized in that: it comprises a compatibilizing agent, a radical copolymerizable unsaturated resin, an addition polymerized polymer and a polymerizable unsaturated monomer, the weight ratio (A1)/(A2) of the principal chain (A1) to the side chain (A2) in the graft copolymer (A) being preferably within a range of 90/10-20/80, and more preferably 80/20-20/80 (% by weight), the graft copolymer (A) being obtained by addition polymerization of an unsaturated monomer containing a styrene monomer which constitutes a principal chain (A1) as a principal component, and a macromonomer which constitutes a side chain (A2) and has a (meth)acrylic residue or styryl residue at one terminal; a molding material containing the radical copolymerizable unsaturated resin composition; and a molded article thereof.
According to the present invention, there can be obtained a practical compatibilizing agent which makes it possible to convert the resin mixture into a homogeneous resin mixture free from separation and to eliminate defects caused by separation during the molding by prevention of the separation between the radical copolymerizable unsaturated resin, and low profile additive (addition polymerized polymer) which could not have been attained by the prior art. Thus, the resin composition obtained by the compatibilizing agent of the present invention cases no separation of the low profile additive. The molding material has an excellent uniformity, therefore makes it possible to obtain a molded article having a very high quality, which is free from scumming and has excellent uniform coloring properties, surface smoothness surface gloss and the like.
The present invention will be described in detail below.
The compatibilizing agent of the present invention is a graft copolymer (A) which contains a styrene monomer as a principal component and has a structure consisting of a copolymer obtained by the addition polymerization of a (meth)acrylic monomer as a principal chain (A1) and a side chain (A2) selected from a ring-opening polymerized polyether side chain which is composed of a polyoxyalkylene ether, preferably containing an oxyethylene unit as a principal component, a polyester side chain, and a polycarbonate side chain. The side chain (A2) is a structure bonded to a functional group-containing unsaturated monomer, for example, (meth)acrylic residue, monovinylbenzyl ether residue (styryl residue) and the like in a principal chain.
The monomer component which can be used to constitute a principal chain (A1) is a styrene monomer alone, or a mixture which contains a styrene monomer as a principal component in combination with (meth)acrylic monomer as the other component. Typical examples of the styrene monomer include styrene, vinyltoluene (methylstyrene), p-methylstyrene, t-butylstyrene, chlorostyrene, vinylbenzyl alkyl ether and the like.
The (meth)acrylic monomer which can be used in combination includes a known (meth)acrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate, glycerin carbonate (meth)acrylate, isocyanate ethyl (meth)acrylate and (meth)acrylate ester. Typical examples of the (meth)acrylate include ester compounds of (meth)acrylic acid with a methyl, an ethyl, a propyl, a butyl, a cyclohexyl, a tert-butylcyclohexyl, a benzyl, a phenyl, an isobornyl, a dicyclopentanyl, a stearyl, a behenyl, a trifluoroethyl, which are added, if necessary.
The side chain (A2) is not limited with respect to the |synthesis procedure, structure or the like, as far as it is at least one side chain selected from polyether, polyester, and polycarbonate. The side chain (A2) is preferably polyether.
As the polyether, for example, there can be used those described below. As the polyester, there can be used saturated and unsaturated polyesters obtained from an xcex1,xcex2-unsaturated carboxylic acid or a saturated carboxyric acid and an alcohol, a polyester obtained by ring-opening polymerization of caprolactone, polycaprolactone, or a polycarbonate obtained by reacting an alcohol, which is described below, with a carbonate such as dimethyl carbonate and diethyl carbonate, which is described below. These are used alone or in combination.
On the other hand, the component which can be used to constitute the ring-opening polymerized polyether. of the side chain (A2) is selected from ring-opening polymerizable monomers, which contains ethylene oxide as a principal component, and which consists of ethylene oxide alone, or other alkylene oxides capable of polymerizing with ethylene oxide or other cyclic compounds capable of ring-opening polymerizing. Other alkylene oxides include propylene oxide, butylene oxide, cyclohexene oxide, tetrahydrofuran, styrene oxide and the like.
Other cyclic compounds capable of ring-opening polymerizing include, for example, acid anhydride compounds such as succinic anhydride and phthalic anhydride, cyclic ester compounds such as caprolactone and valerolactone, and cyclic carbonate compounds such as ethylene carbonate, propylene carbonate and trimethylene carbonate. In addition to non cyclic compounds, there can be also used carbon dioxide capable of polymerizing with alkylene oxide.
The structure of polyether of a side chain (A2) containing ethylene oxide as a principal component, which is obtained by polymerizing the above cyclic compounds is not specifically limited, as far as it exhibits the compatibility with the radical copolymerizable unsaturated resin. The side chain (A2) may be, for example, a random copolymer and block copolymer of ethylene oxide and other cyclic compound. The side chain (A2) may be also extended by using ethylene oxide-type polyether polyol compounds having a molecular weight of less than 1,000 or a glycol compound, and dicarboxylic compounds, diisocyanate compounds, carbonate compounds, diglycidyl ether compounds or the like. Preferably, the number-average molecular weight is within a range of 1,000-20,000, and more preferably within a range of 2,000-10,000. The side chain (A2) may be straight-chain or branched, but straight-chain type is preferable in view of the synthesis procedure.
The number-average molecular weight of polyether of the side chain (A2) is preferably within a range of 1,000-20,000. When the number-average molecular weight of polyether of the side chain (A2) is out of this range, it is difficult to obtain sufficient effects as a compatibilizing agent. It is also difficult to obtain a homogeneous graft copolymer (A) on synthesis. The number-average molecular weight within a range of 3,000-8,000 is particularly preferable.
The amount of oxyethylene units of the side chain (A2) is preferably within a range of 20-100% by weight, and particularly within a range of 60-100% by weight, because the oxyethylene units are closely coordinated with said radical copolymerizable unsaturated resin due to an intermolecular force, functions as an anchor component, which is a very important component for stable dispersion. On the other hand, components constituting preferably 0 to 80% by weight, more preferably 0 to 40% by weight, are polyester chains and/or polycarbonate chains. The side chains may be formed of only one type of these chains. These chains may also be used with ether chains.
Examples of the method of preparing the graft copolymer (A) generally include, but are not specifically limited to, 1) a method of previously synthesizing only a principal chain (A1) and bonding a separately synthesized side chain (A2) in the polymer reaction to obtain a desired (A); 2) a method of previously synthesizing only (A1) and performing the ring-opening polymerization of a ring-opening polymerizable monomer constituting (A2) which starts from an active site in (A1); and 3) a method of the addition polymerization of a saturated monomer constituting (A1) and a macromonomer having a polymerizable function groups capable of polymerizing at one terminal of a chain pre-synthesized to obtain a desired (A), which constitutes a polyether chain (A2). The method of preparing the compatibilizing agent of the present invention is preferably a synthesis method 3) using a macromonomer, capable of easily preparing a homogenous polymer.
The polyether macromonomer which can be used in the graft copolymer of the present invention is a polymerizable functional group capable of polymerizing with an unsaturated monomer which constitutes a principal chain (A1) at one terminal of the above polyether chain (A2). The functional group is preferably an ethylenic unsaturated group. In view of polymerization properties, specific examples thereof include a (meth)acryloyl group and a styryl group are preferable, there can be also mentioned a vinyl group, a propenyl group, an allyl group, a vinyl ether group, an allyl ether group and the like. Typical example of the macromonomer, which can be used in the present invention, are those in which the compound having these functional groups is chemically bonded to the straight-chain polyether at only one terminal.
Specifically, there can be employed mono(meth)acrylate of polyethylene oxide, monovinylbenzyl ether of polyethylene oxide, monovinyl ether of polyethylene oxide, monoallyl ether of polyethylene oxide, monocrotonate of polyethylene oxide, an equimolar-reaction product between isocyanate ethyl methacrylate and polyethylene oxide, a compound obtained by bonding a hydroxyl group-containing unsaturated monomer such as hydroxyethyl (meth)acrylate and polyethylene oxide with a diisocyanate compound such as isophorone diisocyanate and the like. As a result, detailed chemical structure of the macromonomer is not specifically limited, as far as it forms a graft copolymer (A) which functions as the desired compatibilizing agent of the present invention, but employment of a half ester compound of the polyethylene oxide and maleic acid is not preferable in view of the performance.
In the graft copolymer (A), the chemical structure at a free terminal of the side chain (A2) and the structure of other terminal group than the terminal at which a polymerizable functional group of the polyether macromonomer is located are not specifically limited. The structure may have terminal derived from the synthesis conditions of the polyether chain as it is, or may be chemically converted into the other structure. The terminal functional group is preferably a hydroxyl group or an alkoxy ether group. When the molecular weight of the terminal group drastically increases, the content of the oxyethylene units in the polyether chain decreases and, therefore, the compatibilizing effects is likely to become unstable. Accordingly, a polyether side chain with a terminal group structure, which has the number of carbon atoms of 20 or lessor a molecular weight of 500 or less, is preferable.
Examples of usable copolymerizable unsaturated monomer other than the styrene monomer as a principal component, which constitutes the principal chain (A1) of the graft copolymer (A), include an unsaturated carboxylic compound such as (meth)acrylic acid, fumaric acid and itaconic acid, (meth)acrylate monomer having a functional group such as a hydroxyl group and a glycidyl ether group, maleimide monomer such as N-phenyl maleimide, vinyl ester carboxylate monomer such as vinyl benzoate, diester monomer of fumaric acid, mono- and di-ester monomer of itaconic acid, vinyl ether monomer such as cyclohexylvinyl ether. These monomers can be appropriately used, if necessary.
As the principal component in the principal chain (A1), a styrene monomer is preferably used. The amount of the styrene monomer is not specifically limited, but is usually 50% by weight or more, and preferably within a range of 70-99% by weight. Particularly, a styrene monomer is preferably used. The principal chain (A1) is composed of 70-99.9% by weight of styrene monomer and 0.1-30% by weight of other unsaturated monomer including a (meth)acrylic monomer.
The weight ratio (A1/A2) of the main (A1) to the side chain (A2) in the graft copolymer (A) is within a range of 90/10-20/80, preferably within a range of 80/20-20/80, and more preferably within a range of 70/30-30/70 (% by weight). It has been confirmed that a graft copolymer (A) having a composition within a range about 60/40-50/50 (% by weight) can convert a mixture of an unsaturated polyester resin and polystyrene into a homogenous resin mixture free from separation for a long period of one month or more.
The number-average molecular weight of the graft copolymer (A) is not specifically limited, but is preferably within a range of 2,000-100,000, and more preferably within a range of 5,000-50,000. Too small and too large molecular weights give poor effect for a compatibilizing agent. The number-average molecular weight is determined by gel permeation chromatography (GPC).
The synthesis reaction of the graft copolymer (A) in the compatibilizing agent may be carried out in a solvent or without using any solvent. Usually, the reaction is carried out in a solvent in view of working properties. Any solvent may be used as far as it is a solvent in which the compatibilizing agent dissolves, and which does not disturb the synthesis of the graft copolymer. After the completion of the reaction, the copolymer (A) may be isolated from the solvent as a solid matter, or may be present in the reaction solvent. The copolymer (A) is preferably used as it is as far as it can be used as a compatibilizing agent without causing any problem. To lower the viscosity of the solution and to improve the utility, the solution can also be diluted with or redissolved in an unsaturated monomer such as styrene and organic solvent other than the reaction solvent. For example, those, which contain a graft copolymer (A) and an unsaturated monomer or a solvent, are used as a compatibilizing agent composition.
The polymerization initiator in the synthesis of the graft copolymer (A) is not specifically limited, but a radical polymerization initiator, for example, an organic peroxide such as benzoyl peroxide and an azo compound such as AIBN (azobisisobutyronitrile) can be employed. Anion and cation polymerization initiators other than radical polymerized initiator can be used as far as a desired polymer can be obtained.
The amount of the graft copolymer (A), which compatibilizes a radical copolymerizable unsaturated resin with an addition polymerized polymer (thermoplastic resin) added as a low profile additive or a physical properties-improving agent, is preferably within a range of 0.1-10 parts by weight, and more preferably within a range of 0.5-3 parts by weight based on the total of the amount of the radical copolymerizable unsaturated resin and the amount of the addition polymerized polymer as 100 parts by weight. When the amount is smaller than the above range, separation is liable to occur. On the other hand, when the amount is larger than the above range, physical properties are likely to be lowered after the curing.
The radical copolymerizable unsaturated resin composition containing the compatibilizing agent of the present invention is composed of a radical copolymerizable unsaturated resin such as, for example, unsaturated polyester, vinyl ester resin, vinyl urethane resin or acrylic resin, an addition polymerized polymer and a polymerizable unsaturated monomer. If necessary, various additives such as polymerization inhibitors, curing catalysts, fillers, reinforcers, internal mold-releasing agents, and pigments can be added.
The composition of the unsaturated polyester which can be used in the present invention includes, but is not specifically limited to, an unsaturated polyester obtained from the reaction of an xcex1,xcex2-unsaturated carboxylic acid or in some case, an xcex1,xcex2-unsaturated carboxylic acid containing a saturated carboxylic acid with a polyhydric alcohol.
Examples of the xcex1,xcex2-unsaturated carboxylic acid include fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, mesaconic acid, chloromaleic acid, dimethyl esters thereof and the like. These xcex1,xcex2-unsaturated carboxylic acids may be used alone or in combination. The saturated carboxylic acid includes, for example, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, HET(copyright) acid (Occidental Chemical), hexahydrophthalic anhydride, tetrahydro phthalic anhydride, adipic acid, sebacic acid, azelaic acid or the like. These saturated carboxylic acids may be used alone or in combination.
The polyhydric alcohol includes, for example, diols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3-butane diol, 1,4-butane diol, 2-methyl-1,3-propane diol, 1,6-hexane diol, cyclohexane diol, neopentyl glycol, 2,2,4-trimethyl-1,3-pentane diol, 1,4-cyclohexane dimethanol; glycols such as hydrogenated bisphenol A, alkylene oxide adducts of hydrogenated bisphenol A, alkylene oxide adducts of bisphenol A; triols such as trimethylol propane; or tetraols such as pentaerythritol. These polyhydric alcohols may be used alone or in combination.
In addition, the resulting unsaturated polyester may be modified with an epoxy compound such as glycidyl methacrylate, and bisphenol A epoxy, or an isocyanate compound such as toluene diisocyanate and isopropenyl-dimethyl-benzyl isocyanate.
There can be also used dicyclopentadiene unsaturated polyester obtained by adding dicyclopentadiene to the xcex1,xcex2-unsaturated carboxylic acid, saturated carboxylic acid and polyhydric alcohol and reacting them.
A PET unsaturated polyester, which is obtained by using a glycol decomposition product obtained by reacting recovered polyethylene-terephthalate (PET) with a polyhydric alcohol at high temperature as a principal raw material, reacting it with the xcex1,xcex2-unsaturated carboxylic acid, saturated carboxylic acid and polyhydric alcohol, can be used in the present invention without causing any problem.
The vinyl ester resin used in the present invention is a reaction product obtained by the reaction between an epoxy resin and an unsaturated monocarboxylic acid.
The epoxy resin includes, for example, glycidyl ethers of polyvalent phenols such as bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin and brominated epoxy resin; glycidyl ethers of polyvalent alcohols such as dipropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl ether of bisphenol A alkylene oxide adduct and diglycidyl ether of hydrogenated bisphenol A; alicyclic epoxy resins such as 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexane carboxylate and 1-epoxyethyl-3,4-epoxycyclohexane; glycidyl esters such as diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl p-oxybenzoic acid and glycidyl dimer acid; glycidylamines such as tetraglycidylaminodiphenylmethane, tetraglycidyl m-xylylenediamine, triglycidyl p-aminophenol and N,N-diglycidylaniline; heterocyclic epoxy resins such as 1,3-diglycidyl-5,5-dimethylhydantoin and triglycidyl isocyanate; and the like. These epoxy resins may be used alone or in combination.
The unsaturated monocarboxylic acid includes, for example, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, acrylic acid dimer, monomethyl maleate, monomethyl fumarate, monocyclohexyl fumarate or sorbic acid. These acids may be used alone or in combination.
The resulting vinyl ester resin may be further modified with an acid anhydride such as maleic anhydride, succinic anhydride and acetic anhydride or an isocyanate compound such as toluene diisocyanate, isopropenyl-dimethyl-benzyl isocyanate.
A vinyl urethane resin is an oligomer obtained from polyol compounds, organic polyisocyanate compounds, or hydroxyl-containing (meth)acrylates. The polyol compound refers to a generic name of a compound having within a molecule plural hydroxyl groups, but may be a compound having a functional group which has an active hydrogen capable of reacting with an isocyanate group in place of a hydroxyl group, for example carboxyl group, amino group, mercapto group. Such a polyol compound includes, for example, polyester polyol, polyether polyol, acrylic polyol, polycarbonate polyol, polyolefin polyol, castor oil polyol, or caprolactone polyol. These polyol compounds may be used alone or in combination. As the organic polyisocyanate compound, there can be used those described below.
Typical examples of the organic polyisocyanate compound include 1,6-hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, 4,4-dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate and the like. In addition, a multimer obtained by isocyanating each type of isocyanate compound can be included. They are used alone or in combination.
An acrylic resin is composed of a thermoplastic acrylic polymer derived from (meth)acrylate and a polymerizable unsaturated monomer containing (meth)acrylate as a principal component and polymerizable unsaturated monomers. It can be obtained by polymerizing a mixed monomer solution, which contains (meth)acrylate as an essential component and, if necessary, other polymerizable unsaturated monomers capable of copolymerizing with the (meth)acrylates. The acrylic polymer preferably has a molecular weight of 100,000 or less because it is used in a form of syrup dissolved in the polymerizable monomer. The acrylic polymer can be obtained by a common polymerization procedure such as suspension polymerization and solution polymerization. Also, the syrup obtained by prepolymerizing the monomers in a degree of 10-40% can be used as it is.
Typical examples of the polymerizable unsaturated monomer, which can be used in the radical copolymerizable unsaturated resin composition, include known styrenes, acrylates, methacrylates, diallylphthalates, carboxylic vinyl esters, vinyl ethers and the like. However, it is not specifically limited thereto, and can be used by suitably selecting various unsaturated monomers depending on use of the resin solution and required performance.
The amount of the polymerizable unsaturated monomer is not specifically limited, but is preferably within a range of 10-70% by weight, and more preferably within a range of 20-50% by weight, based on (modified) unsaturated polyester, vinyl ester resin, vinyl urethane resin or acrylic resin. The ratio of the radical polymerizable unsaturated resin to the polymerizable unsaturated monomer is preferably within a range from 30-90% by weight to 10-70% by weight, and more preferably within a range from 50-80% by weight to 20-50% by weight, in the resin composition.
The polymerization inhibitor, which can be used in the resin composition of the present invention, is not specifically limited and any conventionally known polymerization inhibitors can be used. Specific examples thereof include hydroquinone, trimethyl hydroquinone, p-tert-butyl catechol, tert-butyl hydroquinone, toluhydroquinone, p-benzoquinone, naphthoquinone, hydroquinone monomethyl ether, phenothiazine, copper naphthenate, copper chloride and the like. These polymerization inhibitors may be used alone, or used after mixing two or more sorts thereof, timely. The amount of the polymerization inhibitor is not specifically limited.
As the curing agent, which can be employed in the resin composition of the present invention, is not specifically limited and any conventionally known curing agents can be used. Examples thereof include one or more selected from heat-curing agents, ultraviolet-curing agents, electron radiation-curing and the like. The amount of the curing is preferably within a range of 0.1-10 parts by weight, and particularly within a range of 1-5 parts by weight based on 100 parts by weight of the resin composition.
The heat-curing agent includes an organic oxide, for example, known diacyl peroxide, peroxy ester, hydroperoxide, ketone peroxide, alkyl perester, percarbonate compounds. The heat-curing agent can be appropriately selected according to the molding condition.
Th The ultraviolet-curing agent is a photosensitizer, for example, known acylphosphine oxide, benzoyl ether, benzophenone, acetophenone, thioxantone compounds. The ultraviolet-curing agent can be appropriately selected according to the molding condition. The electron radiation-curing agent includes halogenated alkylbenzene, disulfide compounds and the like.
Examples of the additive capable of accelerating curing (curing accelerator) which is used in combination with the above described curing agent includes, but is not limited to, metal salts such as cobalt naphthenate and cobalt octonate, tertiary aromatic amines such as N,N-dimethylaniline, N,N-di(hydroxyethyl) p-toluidine and dimethylacetoacetamide and the like. They are selected, if necessary.
Typical examples of the filler, which can be used in the resin composition of the present invention, include calcium carbonate, magnesium carbonate, barium sulfate, mica, talc, kaolin, clay, Celite, asbestos, perlite, baryta, silica, quartz sand, dolomite, limestone, gypsum, aluminum fine-powder, hollow balloon, alumina, grass powder, aluminum hydroxide, white marble, zirconium oxide, antimony trioxide, titanium oxide, molybdenum dioxide and the like. These fillers are selected in view of the workability, strength and appearance of the resulting molded article, economical efficiency and the like, but calcium carbonate, aluminum hydroxide, silica, and talc are commonly used. The filler also includes surface-treated one.
The reinforcers which can be used in the resin composition of the present invention may be those which are usually used as fiber reinforcers. Examples thereof include grass fiber, polyester fiber, phenol fiber, polyvinyl alcohol fiber, aromatic polyamide fiber, nylon fiber, carbon fiber and the like. These reinforcers may be in the form of chopped strand, chopped strand mat, roving, textile and the like. These reinforcers are selected in view of the viscosity of the composition, strength of the resulting molded article and the like.
Examples of the internal mold-releasing agent which can be used in the resin composition of the present invention include higher fatty acid such as stearic acid; higher fatty acid salt such as zinc stearate; and alkyl phosphate. However, it is not specifically limited thereto and various mold-releasing agents selected suitably depending on the molding condition can be used
Typical examples of the pigment, which can be used in the resin composition of the present invention include, inorganic pigments such as titanium white and carbon black, and organic pigments such as phthalocyanine blue and quinacridone red. Various pigments can be used depending on color phase. In general, the pigments are often added as a toner in which the pigments are uniformly dispersed into an unsaturated polyester resin and the like.
Other various additives includes viscosity modifiers such as viscosity reducing agents, defoaming agents, silane coupling agents, air-blocking agents such as paraffin and the like. Commercially available products can be used.
When preparing molding materials such as seat molding compound (hereinafter referred to as SMC) and bulk molding compound (hereinafter referred to as BMC), the thickening agent includes metal oxides, hydroxides such as magnesium oxide and calcium hydroxide and multifunctional isocyanate compounds such as crude MDI. However, the thickening agent is not specifically limited thereto and various thickening agents selected suitably depending on use of the molding material and required performance can be used. In general, magnesium oxide capable of easily controlling the degree of thickening is used.
In the present invention, the addition polymerized polymer (thermoplastic resin), which is mixed with the radical polymerizable unsaturated resin is not specifically limited, but an addition polymerized polymer which exerts desired effects such as low profile and improvement of physical properties (fracture toughness, etc.) can be suitably selected depending on use of molding, molding condition and the like and used. Typical examples thereof include polystyrene resin containing styrene as a principal component, for example, polystyrene, styrene-((meth)acrylic ester) copolymer, styrene-(conjugated diene) block copolymer, hydrogenated styrene-(conjugated diene) block copolymer and the like. In addition, no styrene containing (meth)acrylate polymer, for example, poly(methyl methacrylate), poly(n-butyl acrylate) ester and the like is also included. There can be also used those obtained by reacting double bonds in these polymers with other compounds.
The styrene-(conjugated diene) block copolymers are block copolymers made of styrene components obtained by polymerizing styrene with conjugated butadiene and conjugated diene components. As the conjugated diene components, there can be used butadiene, isoprene, 1,3-pentadiene and the like. In addition, styrene-hydrogenated conjugated diene block copolymer obtained by hydrogenating these styrene-(conjugated diene) block copolymer may be also used. The unit of the block copolymer is not specifically limited, but includes repeat units of styrene and conjugated diene such as styrene-(conjugated diene), styrene-(conjugated diene)-styrene, and (conjugated diene)-styrene-(conjugated diene). Specific examples thereof include styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-(ethylene butylene) block copolymer, styrene-(ethylene propylene) block copolymer and the like.
The resin composition of the present invention can be used as, for example, a molding material (for press molding and injection molding as SMC and BMC, spray molding, hand lay-up molding, casting, pultrusion), coating material (paint, putty, cosmetic plate, sealing material, and lining material). The molding material of the present invention contains resin compositions, polymerization inhibitors, curing agent, fillers, reinforcers and if necessary, various additive such as internal mold-releasing agents and pigments.
Examples of the molding article of the present invention include house equipment such as bathtub, kitchen counter, lavatory, waterproof pan and septic tank; civil building materials such as artificial marble, panel, corrugated board, drawn material and polymer concrete; marine structures such as boat and ship; automobile parts such as lamp reflector; commodities such as buttons and boring ball; and the like.